Advertising helps fund great web services and enables companies of all sizes to grow their businesses online. However, this economy can also attract bad actors that want to abuse online advertising tools for harmful or deceptive purposes.

We've allocated substantial technical, financial, and human resources to stopping bad advertising practices and protecting users on the web. Hundreds of our engineers, policy experts and others have dedicated their careers to this work.

Following up on our 2012 report, below is an overview of how we fought bad ads and bad ad-funded content in 2013.

Stopping more bad ads from fewer bad sources

We removed more than 350 million bad ads from our systems in 2013. To put that in perspective, if someone looked at each of these for one second, it would take them more than ten years to see them all. This was a significant increase from approximately 220 million ads removed in 2012. This trend has been consistent in the last several years and we attribute it to several factors, including: the growth of online advertising overall and constant improvement of our detection systems.

The number of advertisers we disabled, however, dropped from over 850,000 in 2012 to more than 270,000 in 2013. In part, we attribute this decline to scammers — counterfeiters, for example — being thwarted by our safety screens and searching for less-secure targets.

Counter-attacking counterfeiters

We continue to see positive results in our work to combat counterfeiters. Attempts to market counterfeit goods on AdWords decreased by 47% in 2012 and 82% in 2013. In parallel, the volume of complaints about these ads dropped by 85% in 2012 and by another 78% in 2013.

As these numbers have declined, we’re pleased to report that we’ve also banned fewer bad advertisers for counterfeit violations. Last year, we banned approximately 14,000 advertisers for trying to sell counterfeit goods — a decline of more than 80% compared to 2012.

Preventing good ads from funding bad content

Maintaining a healthy ads ecosystem isn’t just about stopping bad ads and advertisers; we closely monitor the sites and mobile apps that show our ads as well. Early last year, we outlined some of this work, with a particular focus on our efforts to stop scammy ad-funded software, like toolbars, that provides a poor user-experience.

By the end of 2013, we had blacklisted more than 200,000 total publisher pages, an encouraging decline from last year, and disapproved more than 3,000,000 attempts to join our AdSense network. We also removed more than 250,000 publisher accounts for various policy violations. This includes more than 5,000 account removals for violating our copyright policies, an increase of more than 25% compared to 2012.

Here’s a more complete overview of our work to bust bad advertising practices in 2013:

This is an ever-evolving and ongoing fight. Bad actors are relentless, often very sophisticated and will not rest on their laurels. But neither will we. Nothing is more important than the security of our users and we’ll continue to work tirelessly to keep them safe online.